A conventional game machine controller 1 (first prior art controller) shown in FIG. 1 includes a rectangular housing 1a, a select switch 3 for selecting a game content, a start switch 2 for designating a start of the game, a cross direction switch 4 for designating a moving direction of a game character during the game, and two action switches 5a and 5b for selecting or designating an action of the character, all the switches being provided on an upper surface of the housing 1a. Since a processing capability (a processing capability of a CPU) of a conventional game machine was relatively low in comparison with a present game machine, it was possible to sufficiently enjoy the game with using first prior art controller 1. However, as the game content became more complex, it became impossible to sufficiently control the action of the character by using only the two action switches 5a and 5b.
Therefore, a game machine controller 1 (second prior art controller) shown in FIG. 2 has been proposed and put into practical use. In the second prior art controller 1, various kinds of switches are provided on an upper surface of a housing 1a' having a circular surface. More specifically, in the second prior art controller 1, in addition to the select switch 3, the start switch 2 and the cross direction switch 4, four action switches 5a, 5b, 5c and 5d are provided on the surface of the housing 1a', and two switches 6a and 6b are provided on a rear surface of the housing 1a' at positions that index fingers or middle fingers of both hands can reach while the palms of both hands are brought into contact with left and right side surfaces of the housing 1a'.
In the second prior art controller 1, an outer shape of the housing is designed in a manner that the side surfaces of the housing 1a' fit the palms of both hands when grasping the housing 1a'. Accordingly, the switches can be operated without large movements of the fingers. The action switches 5c and 5d, and the left and right switches 6a and 6b are newly provided. Therefore, the operator can operate the respective switches without looking at them and with thus watch the screen of the monitor only. However, in a case of a game that it is required to frequently and rapidly operate a plurality of switches, there was a possibility that a positional relationship between the controller and the hands, i.e. a positional relationship between the respective switches and the fingers might change from an original positional relationship.
Therefore, a controller 1 (third prior art controller) shown in FIG. 3, in which no change occurs in the positional relationship between the controller and the hands has been proposed and put into practical use. In the third prior art controller 1, a cross direction switch 4a and action switches 5a and 5b, and a cross direction switch 4b and action switches 5c and 5d are arranged on left and right housings 1a and 1b, respectively. Furthermore, there are provided with two grips 7a and 7b extended from the housings 1a and 1b, and grooves 8a and 8b are formed on rear surfaces of the grips 7a and 7b. By firmly holding the grips 7a and 7b by inserting fingers into the grooves 8a and 8b, it is possible to securely restrict the hands of an operator, i.e. maintain the fingers at constant positions, and therefore, the respective switches can be surely operated.
On the other hand, in the prior art controllers shown in FIG. 1 to FIG. 3, a direction signal for designating a direction that an image on the monitor is to be moved is outputted by utilizing the cross direction switch 4 or 4a (and 4b). However, in the conventional cross direction switch, switch contacts are provided at four directions of upper (North), lower (South), left (West) and right (East) on the monitor screen, that is, at four directions of front, rear, left and right in a case where the controller is viewed in plain. According to a switch contact being turned-on, the direction signal which designates one of the four directions can be outputted. That is, the cross switches provided in the conventional controllers is a kind of digital joystick. Therefore, there was a problem that the operator could designate an arbitrary direction other than one of the four directions.
Accordingly, it is possible to consider that there is provided with an analog joystick on such a game machine controller. Meanwhile, a term "analog joystick" means a device which is provided with a lever, and can output a direction signal determined by a direction in which the lever is inclined. In such an analog joystick, there is an advantage that it is possible to designate all directions in 360 degrees. However, there is a further disadvantage to be solved that an operation of the lever is insecure.
More specifically, if a finger is detached from the lever to release the operation of the lever, the lever returns to its home position (normally, a position that the lever stands upright). Although the lever is secure at the home position, a position of a finger of the operator primarily defines a direction that the lever is inclined or an amount that the lever is inclined. Thus, it is difficult for a person who can not finely control the position of the finger to stably operate the lever. A controller for television game machine for home use is normally held by hands of the operator to operate respective switches or keys provided on the controller. In a case where the analog joystick is provided on such a hand-holdable controller, the above described problem that the operation of the lever can not be securely performed becomes more significant.
Therefore, in a case where a controller with an analog joystick is used in a home video game machine, for example, it is possible to easily determine that there is a problem wherein a movable character can not be moved in a desired direction when the direction that the movable character (image) displayed on the monitor screen is to be finely controlled on the screen with the analog joystick. Especially, in the video game, there are a relatively large number of scenes wherein the movable character is continuously moved in one direction without zigzagging, and in such a scene, stable operation of the analog joystick is especially required.